This invention relates generally to the feeding of lengths of electrical wire and the like and, more particularly, to a feeding method and apparatus which maintains pressure on the wire being fed within a predetermined range regardless of variance in the actual size of the wire.
It is a conventional practice in the electrical wire lead manufacturing industry to feed a predetermined length of wire from a substantially endless supply and install electrical connectors thereon or perform other operations to manufacture a completed electrical product. An example of such an automatic manufacturing technique and apparatus is disclosed in U.S. patent application Ser. No. 207,046, entitled, "Automatic Lead Making Apparatus". filed in the names of Ernest L. Cheh, Et Al on Nov. 14, 1980. There are a multitude of other manufacturing applications beyond that disclosed in this co-pending patent application in which it is necessary to feed a length of material, or a plurality thereof, to work stations in a reliable and controlled manner.
One continual problem in feeding lengths of wire is that all portions of the wire are not of a uniform size. For any given nominal size of wire, the manufacturing techniques allow some range of sizes through which the actual size can vary. This problem can be acute when feeding the wire through the nip of two rollers. In this type of feeding system, the rollers must be set at some gap to insure continuous driving contact with the wire. For instance, the size of the gap between the rollers can be set equal to the smallest size of the wire and continuous feeding is assured. However, this approach creates the problem of damaging the portions of the length of wire having larger sizes. The wire tends to be compressed more greatly by the increased force placed on it as larger sizes pass through the small gap.
When electrical wire is fed in this manner, the insulation around the conductor can be damaged and the strength and durability of the both wire materials can be compromised. Depending upon the severity, the wire can be rendered unusable. When feeding a plurality of wires between the rollers, the problem is further compounded in that each length of wire is varying in size. Also, the feeding of a plurality wires normally requires a large and complex apparatus.
Accordingly, it is an object of the present invention to provide an improved feeding device for wire and the like without damaging the wire even though the size of the wire varies.
It is another object of the invention to provide a roller-type feeding means for lengths of wire and the like which applies approximately the same amount of pressure on the wire even though the size of the wire varies.
It is another object of the invention to feed a plurality of lengths of wire and the like with a feeding means which applies approximately the same amount of feeding pressure on the wire even though the size of the wire varies.
It is another object of the invention to feed different nominal sizes of wires in adjacent paths by using the same feed roller means.
It is another object of the invention to provide a compact apparatus for feeding a plurality of lengths of wire and the like.